1. Field of the Invention
The present invention relates to the preparation of hydrogenated silanes by redistribution, and, more especially, to the preparation of a silane containing at least one Si--H bond by reacting a less hydrogenated or non-hydrogenated silane with an alkyl or aryl hydrogenosilane in the presence of a catalyst system.
2. Description of the Prior Art
It is known to this art to prepare silanes containing at least two Si--H bonds by dismutation of two molecules of a hydrogenosilane optionally comprising alkyl or aryl groups. Thus, French Pat. Nos. 2,096,605, 2,118,725, 2,261,977, 2,290,447, and 2,290,448 describe such dismutation reactions in the presence of various catalysts, wherein such dismutation reactions can be represented as follows: EQU 2R.sub.n H.sub.m SiX.sub.4-(n+m) .revreaction.R.sub.n H.sub.m+1 SiX.sub.3-(n+m) +R.sub.n H.sub.m-1 SiX.sub.5-(n+m)
in which n denotes an integer equal to 0, 1 or 2; m denotes an integer equal to 1, 2 or 3 with n+m.ltoreq.3, and R denotes an alkyl or aryl group and X a halogen
It is also known to prepare alkyl or aryl hydrogenosilanes by redistribution between a molecule of a hydrogenosilane and a molecule of alkyl or aryl halosilane. The described catalysts for these redistribution reactions are notably those which are the subject of French Pat. Nos. 1,603,167, 2,290,447, 2,467,855, 2,290,448, 2,096,605 and 2,119,477, wherein such redistribution reactions can be represented as follows: EQU H.sub.m SiX.sub.4-m +R.sub.n SiX.sub.4-n .fwdarw.H.sub.m-1 SiX.sub.5-m +R.sub.n HSiX.sub.3-n
in which m denotes an integer equal to 1, 2, 3 or 4 and n denotes an integer equal to 1, 2 or 3 and R denotes an alkyl or aryl group and X a halogen.